Characteristics of Botryllus schlosseri

Botryllus schlosseri
Colony
Shape flat
Thickness (mm) 1.0-1.5
Arrangement of zooids orval
Tunic transparent, gelatinous, soft,
Ampullae size (mm: L x W) 0.7 x 0.2
Formation of colony part including only vascular system infrequently
Color of pigment cells forming pattern on a colony surface white, yellow
Pattern by deposited pigment cells single pattern
Zooid
Length (mm) 2.0-2.8
Ground color orange, blue, brown
Number of tentacles (Large),(Small),(Minute) L4, S4
Number of stigmatal rows 8
Second row of stigmata incomplete
Number of longitudinal vessels 3
Number of stomach plication 8
Pyloric caecum large
Asexual reproduction
Peribranchial budding all seasons
Number of buds in each zooid R1-2, L 1-2
Vascular budding infrequently
Cycle of takeover one week
Sexual reproduction
Breeding season Mar-Nov
Arrangement of gonads (position of ovary) anterior to the testis
Testis shape & color rosette, white opalescent
Color of eggs yellowish orange
Production of larvae ovoviviparous
Mature egg diameter (µm) 230-250
Number of mature eggs L &R: 1-3
Brooding organ oviducal cup formed from atrial wall
Embryo size just before hatching (µm) 280-300
Development to larvae in one week
Release of larvae shortly before degeneration of parent zooids
Larva
Length (mm) 1.6
Length of larval trunk (µm) 400
Number of larval ampullae 8
Oozooid
Length (µm) 500
Number of tentacles -
Number of protostigmata L4, R4-5
Number of stomach plication 5
Number of buds R1
Colony specificity
Present or absent present
Starting stage of allorejection before tunic fusion
Occurrence of subcuticular rejection no
References Boyd et al.,1990
- : not examined

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